<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            width:200px;
            height:200px;
            border: 4px solid black;
            padding: 20px;
        }
        .big{
            width:300px;
            height:300px;
        }
        .pink{
            background: pink;
        }
    </style>
</head>
<!-- 
    :class 后面可以接数组和大括号
    大括号 :class="{[pink:true,big:true]}" 适用于类名来回切换
    数组 :class="['box','pink','big']" 批量添加或删除类
 -->
<body>
    <div id="app">
        <div  :class="['box','pink']"></div>
    </div>
    <script src="./vue.js"></script>
    <script>
        const app = new Vue({
            el:'#app',
            data:{

            }
        })
    </script>
</body>
</html>